Screening of N-ras Gene Mutations in Urothelial Cell Carcinomas of the Urinary Bladder in the Kashmiri Population


Background and Aims: The objective of this study was to assess the frequency of specific-point mutations inN-ras of the RAS gene family in a group of Kashmiri patients with bladder cancer and to observe any associationwith clinicopathological parameters.
Methods: Paired tumor and normal tissue specimens of 55 consecutivepatients with urothelial cell carcinoma were screened and DNA was extracted for detection of N-ras activatingmutations in exons 1 and 2. In addition, blood was also collected from all the cases to rule out any germ linemutation.
Results: Specific point mutations of activated N-ras were detected in 9% (5 of 55) of the bladdercancer patients, all being missense. The base substitutions identified included three transversions (two G toTand one A to T) and two transitions ( A-G). Sixty % of the mutations were detected in codon 61 and 40% incodon 12. No significant correlations were found between the mutations and clinical features.
Conclusion:Although N-ras gene mutation might be one of the mechanisms underlying oncogenesis of urothelial cancer, itseems to be a relatively rare event in Kasmiris, pointing to involvement of different etiological factors in theinduction of bladder tumor in this population